The rood is a unit of area used in historic England with the symbol ro.
Its unit size is equal to 1/4 of an acre, 10,890 ft² or 1,012m². A rectangle equal to one furlong in length and one rod in width is one rood in area.
Its use was very important in surveying land because of the ease of conversion into acres from smaller sections of land.
The square centimetre is a unit of area and is a multiple of the square metre; an SI derived unit. It has the symbol cm².
A square centimetre is equal to the area of a square with edges 1cm long. There are 10,000 square centimetres in a square metre.
It is often used to describe areas smaller than 1m² - including much work in classrooms on paper.